The main source of heat within planetesimals is the radioactive decay of both short- and long-lived radionuclides. In Fig. REF  we plot the total energy output as a function of time for some short-lived radionuclides. Because serpentinization is a rapid process, only a few 10,000 years, we investigated the early stages of the heat development of planetesimals. During this period, as shown in Fig. REF , the most significant portion of the heat production from radioactive decay was provided by \(^{26}\) Al [1]}, and only this isotope was considered in our thermal evolution model as a heat source, with the following parameters: half-life is t\(_{1/2}=0.717\)  Myr, total energy is TE\(=5.07 \times 10^6\)   J/kg, and we assume that \(^{26}Al\)  was homogeneously distributed in the early solar system [1]}.
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